while I was trying weather routing (which works nicely) I found some shortcomings in the area of GRIB file handling:

the information that the grib plugin shows about loaded grib files is very sparse. All I can find is the list of timestamps. Should we not show the first and last timestamp, number of loaded grib files, and perhaps even the list of loaded files and holes in the resulting timespan?

It is not very clear which operations reset the list of loaded GRIB files, and which ones add to the list.

If no GRIB file is loaded, the plugin tries to load the newest GRIB file. This is based on filename suffixes, including suffixes ".bz2" and ".gz" which are also used for non-GRIB files, resulting in a "this is not a GRIB file" error. Should we not ignore such files if they are not GRIB files?

I might start sending patches for this, but seems the whole GRIB handling is already worked on by others so that might be a waste of time. Please advise.

Yes, correct. I do not plan to change that. I just want to avoid that O shows the error "famous_quotes.gz is not a valid GRIB file" just because that file is newer than the recently downloaded grib file in the same directory.

Saw your pr. Format and data checking is good but how would we be able to test new grib types if restricted, limited?

My proposed patch only changes the behavior of "getLatestGribFileFromDIrectory" which tries to automatically load the latest (and thus presumably most likely wanted) GRIB file when the plugin starts. You can always use the file chooser to load other GRIB files. Sorry for not making that clearer.

Apologies again, I should have provided a lot more detail the first time.

My comments for both the tablet and laptop Windows 10 were referring to OpenCpn 4.2.0.

I did try 4.2.1724 a while ago but the routing would not work, I think due to an incompatibility with the Grib plugin. If there are new versions of the plugins that I can download in compiled form I'd be happy to try them out again.

Apologies again for not being clear the first time.

Yesterday I did a 45 nm passage taking the route suggested by the routing plugin on 4.2.0 and we arrived within ten minutes of the predicted time.

Please refer to Weather Routing I found Pavel's earlier version (fork of Sean's repos) works under Windows Opencpn v4.2.0.

There was some guy who wanted Climatology Weather_routing run from Falmouth to LasPalmas. Because weather_routing wasn't working in 4.2 + I went back to v4.0 but found that Climatology for 3.2 does not work with v4.0 (of course it doesn't, we changed wxwidgets version)! Therefore there is NO version of Climatology on the Download page that works with Opencpn v4.0. This is probably the same situation with many plugins. I've deleted all the v4.0 plugins that I built, thinking they were on the website download page.

Anyway, I can't seem to find the Falmouth to Las Palmas guys post. - So it is run at the link above. Takes about 4 days starting today, with a fast boat 60ft_multi_3.pol was used.